Which of the following reaction will be least forward ?
(i)`N_(2(g)) +O_(2(g)) hArr 2NO_((g)) , K_c=4.8xx10^(-31)` at 298 K
(ii)`Fe_((aq))^(3+) +SCN_((aq))^(-) hArr [Fe(SCN)]^(2-) , K_c`= 140 at 298 K
(iii)`H_(2(g)) + Cl_(2(g)) hArr 2HCl_((g)), K_c=5xx10^31` at 298 K

Explanation

(i)`K_c` of this reaction is much less so it is so far of completion.